A laser module for converting an electric input signal into an optical output signal is disclosed in published German Pat. No. 33 07 933. In that laser module, the bottom of the housing supports a cooling device on which the heat sink with the laser and the drive circuit is disposed. The end of the optical fiber, which is aligned to the active area of the laser, is embedded in a sleeve in a gastight manner, and the sleeve is hermetically sealed in bushing mounted in a sidewall of the housing. The materials used for the individual components are chosen to have the same coefficient of expansion or coefficients of expansion differing from each other as little as possible. This is to ensure that the heat produced during operation of the laser will not cause any misalignment of the fiber end. However, due to the separation between the laser support and the fiber holder, even small compressive forces applied unintentionally to the sidewall of the housing or to the bushing may cause a misalignment of the fiber end in front of the laser and, thus, a failure of the coupling arrangement.